88984 ÷ 21 
The aim is to understand the frequency of 21 in 88984.

Let's proceed to step 1:
When dividing 8 by 21, we get 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (8) from the dividend, add it to 8, then carry on: 88 / 21

Advancing to step 2:
88 divided by 21 is 4 with a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Subtracting 84 from 88 leaves us with 4.
Grab the next digit (9) from the dividend, add it to 4, then carry on: 49 / 21

On to step 3:
When dividing 49 by 21, we get 2 with a remainder of 7.
Put 2 as the next digit of the answer. 
Result so far: 42.0
Deduct 42 from 49 and we're left with 7.
Include the next digit (8) from the dividend after 7, then repeat: 78 / 21

On to step 4:
If we divide 78 by 21, we get 3 and a remainder of 15.
Record the quotient 3 as the next digit in the result. 
Result so far: 423.0
Subtract 63 from 78 to get 15.
Fetch the next digit (4) from the dividend, attach it to 15 and continue: 154 / 21

On to step 5:
The number 21 fits into 154 7 times, leaving a remainder of 7.
Put 7 as the next digit of the answer. 
Result so far: 4237.0
Deduct 147 from 154 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 6:
21 can be fit into 70 3 times, resulting in a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 4237.3
If we subtract 63 from 70, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 7:
21 goes into 70 3 times with a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 4237.33
Subtract 63 from 70 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

After the division, we end up with 4237.33 and a remainder of 0.007.